JP5532526B2 - camera - Google Patents

Description

  The present invention relates to a camera in which a taking lens can be exchanged.

A camera that can exchange a photographic lens includes, for example, an acquisition unit that acquires optical characteristic information (for example, an open F number and an aperture efficiency) of a photographic lens stored in a memory included in the photographic lens, and a subject through the photographic lens. Metering means for metering the incident light.
The photometric result (for example, exposure amount) measured by the photometric means is corrected using the optical characteristic information acquired by the acquiring means (for example, Patent Document 1). In general, in this type of camera, optical characteristic information for correcting the photometric result is corrected using correction information for correcting the optical characteristic information.
JP-A-4-240833

  However, in the above-described camera, the optical characteristic information of the photographic lens is corrected using, for example, a value obtained by averaging correction information of all the photographic lenses. This value is calculated by averaging the correction information of the old photographic lens. The new photographic lens is not included in the old photographic lens. As a result, there is a problem that the optical characteristic information of the new photographic lens cannot be corrected accurately.

  An object of the present invention is to accurately correct optical characteristic information of a new type of photographing lens in a camera that corrects optical characteristic information of the photographing lens using correction information.

In one aspect of the present invention, the camera connects information acquisition means for acquiring lens identification information and optical characteristic information as specific information of the shooting lens from a shooting lens attached to the camera body, and connects the camera body to a computer network. When the lens identification information is acquired from the photographing lens by the connecting means and the information acquisition means, correction information corresponding to the lens identification information and for correcting the optical characteristic information acquired from the photographing lens is obtained. Based on the identification information, if the lens acquisition information is not acquired from the taking lens by the information acquisition means while the lens acquisition information is not acquired from the photographic lens , the stored information is not acquired without performing the operation of acquiring the correction information from the computer network . a correction information acquisition means for the correction information obtained by averaging the correction information for all the photographic lens value, And an information correcting means for correcting the optical characteristic information by using the correction information acquired by the positive information acquisition means.
As a technique related to the present invention, in the camera of the first technique, the information acquisition means receives specific information of the lens from a lens attached to the camera body. The connection means connects the camera body to the computer network. The correction information acquisition unit acquires correction information for correcting the optical characteristic information corresponding to the unique information received by the information acquisition unit from the computer network. The information correcting unit corrects the optical characteristic information using the correction information.

In the camera of the second technology , the connection means includes communication terminal connection means for connecting the camera body to the communication terminal in order to connect the camera body to the computer network via the communication terminal.
In the camera of the third technology , the connection means includes wireless connection means for connecting the camera body to the computer network in a wireless manner.

In the camera of the fourth technology , the photometric means measures the light incident from the subject through the lens attached to the camera body. The photometry correction unit corrects the photometry result obtained from the photometry unit using the optical characteristic information corrected by the information correction unit.
In the camera according to the fifth technology , the storage means has a plurality of storage areas for storing the correction information in association with the lens. The information writing unit writes the correction information in the storage unit. The information writing means sequentially writes the correction information acquired by the correction information acquisition means to the empty area when the storage area is empty, and the correction information acquired by the correction information acquisition means when the storage area is not empty. The oldest correction information is replaced and stored. The information correction unit corrects the optical characteristic information using correction information stored in the storage unit and corresponding to the lens attached to the camera body.

In the camera of the first technology , correction information corresponding to optical characteristic information (for example, exit pupil position, aperture efficiency, open F number, etc.) possessed by the lens is acquired via a computer network. That is, the correction information can be acquired for each lens. For this reason, for example, even when a lens is newly released, the optical characteristic information is accurately corrected by the information correction unit using the correction information acquired for each lens by the correction information acquisition unit. By using the optical characteristic information of the lens that has been accurately corrected, it is possible to optimally adjust the exposure, focus, and the like to image the subject. For this reason, an image having a quality intended by the photographer can be obtained.

In a second technique of camera, the camera body is connected to a computer over a network via the communication terminal. Therefore, it is not necessary to mount the hardware required to connect computers over the network to the camera body. Therefore, the mechanism of the camera body can be simplified. Since the number of manufacturing steps and the number of parts for manufacturing the camera body can be reduced, the manufacturing cost of the camera body can be reduced.

In the third technology camera, the camera body is connected to the computer network in a wireless manner. There is no need to attach a wired cable to the camera body to connect the camera body to the computer network. Since there is no restriction due to the cable length, the camera body can be easily moved while connected to a computer network.
In the camera according to the fourth technique , the photometric result (for example, the exposure amount) is accurately corrected using the optical characteristic information (for example, the exit pupil position and the aperture efficiency) accurately corrected by the information correcting unit. By using this photometric result, the subject can be imaged with an optimum exposure. For this reason, the brightness of the subject image can be optimized.

In the camera of the fifth technique , the information writing unit writes correction information corresponding to the replaced lens in the storage unit each time the lens is newly replaced. The written correction information is used for correcting the optical correction information of the new lens by the information correction means. In general, when a user replaces a new lens, the frequency with which the old lens attached to the camera body before replacement is used by the user is low. The correction information corresponding to the old lens (written old by the information writing means) is less frequently used for correcting the optical characteristic information. In the present technology , the information writing unit replaces the correction information with the oldest written correction information (the least frequently used for correcting the optical characteristic information) and stores the correction information in the storage unit. For this reason, even when the size of the storage area of the storage means is limited, correction information that is frequently used can be left in the storage area. As a result, the storage area of the storage means can be used effectively.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment of the camera of the present invention. FIG. 1A shows a camera 100 (for example, a digital camera) to which the present invention is applied.
The taking lens 104 is detachably attached to a lens mount formed in the center of the front surface of the camera body 102 of the camera 100. By attaching the photographing lens 104 to the camera body 102, the camera body 102 and the photographing lens 104 are connected via a communication line (not shown).

A liquid crystal monitor LCD (Liquid Crystal Display), which will be described later, is disposed on the back surface of the camera body 102 (the surface opposite to the mounting position of the photographing lens 104). Various switches including switches SW1, SW2, and SW3 are arranged on the upper surface of the camera body 102. Various switch operations are recognized by a CPU (described later) built in the camera body 102.
The main power switch SW1 turns on or off the power of the camera 100. The shutter switch SW2 is pressed down when shooting a subject. The selection switch SW3 is a switch for the user to change various settings of the camera 100 in accordance with the display screen of the liquid crystal monitor LCD.

  The camera 100 receives parameters (optical characteristic information such as exit pupil position, aperture efficiency, open F number, etc.) of the photographic lens 104 from the photographic lens 104 via a communication line. The camera 100 corrects the parameter received from the photographic lens 104 using correction information set according to a lens identification ID (described later) that is data for identifying the photographic lens 104. The camera 100 determines shooting conditions (for example, exposure amount and focal length) based on the corrected parameters.

FIG. 1B shows a personal computer 106 (communication terminal). The personal computer 106 has a display for displaying a screen, a keyboard for inputting instructions, and the like.
The camera 100 is connected to the personal computer 106 via, for example, a USB cable 108 in order to acquire correction information of the photographing lens 104. The camera 100 is connected to the Internet 110 (computer network) via the personal computer 106.

  The camera 100 is connected to the Web server 112 via the Internet 110 and acquires correction information of the photographing lens 104 from the Web server 112. The correction information acquired from the Web server 112 is transmitted to the camera 100 via the Internet 110 and the personal computer 106. The correction information transmitted to the camera 100 is stored in the ROM 16 (FIG. 2) mounted inside the camera 100.

  FIG. 2 shows an internal configuration of the camera 100 and the photographing lens 104 shown in FIG. The camera 100 includes a photometric sensor 10 (photometric means), a CCD (Charge Coupled Device) 12, an A / D conversion circuit 14, a ROM 16 (storage means), a CPU 18, an I / F (Interface) circuit 20 (communication terminal connection means). A liquid crystal monitor LCD 22, a bus 24, a RAM (not shown), and the like. In FIG. 2, main elements of the electrical system of the camera 100 are shown. Illustration of mechanical elements such as a shutter mechanism and a mirror mechanism is omitted.

  The photometric sensor 10 photoelectrically converts light incident from the subject via the lens system 22 of the photographic lens 104 in order to acquire the exposure amount E of the camera 100. The CCD 12 is disposed at a position facing the lens system 26 via a shutter. The CCD 12 is driven by a CCD driver (not shown) and photoelectrically converts a subject image formed by the lens system 26. The A / D conversion circuit 14 A / D converts the exposure amount E photoelectrically converted by the photometric sensor 10 and the image captured by the CCD 12 from an analog value to a digital value. The A / D conversion circuit 14 outputs the exposure value which is a digital value of the camera 100 and the image data of the subject to the CPU 18.

  The ROM 16 stores a program executed by the CPU 18 for operating the camera 100. The ROM 16 is configured by an EEPROM, a flash memory, or the like that can electrically rewrite data. The ROM 16 stores correction information described later in association with a lens identification ID described later. Note that the ROM 16 can be replaced by a ROM (not shown) that is mounted on the CPU 18 and can electrically rewrite data.

  The CPU 18 controls the operation of the camera 100 by executing a program stored in the ROM 16. For example, the CPU 18 corrects parameters to be described later using the correction information. The I / F circuit 20 connects the camera 100 to the personal computer 106 (FIG. 1) via the USB cable 108 (FIG. 1) in order to obtain correction information from the Web server 112.

The liquid crystal monitor LCD 22 is driven by the CPU 18. For example, the liquid crystal monitor LCD 22 displays a screen for changing the settings of the camera 100 in response to pressing of various switches (FIG. 1) by the user. The bus 24 connects each circuit in the camera 100.
The photographing lens 104 includes a lens system 26, a lens ROM 28, a lens driving circuit (not shown), a diaphragm, a diaphragm driving circuit, and the like. The lens system 26 includes a plurality of lenses including a focus lens that focuses on the subject and a zoom lens that zooms the subject image. The position of the focus lens and the zoom lens in the optical axis direction is adjusted by a lens driving circuit.

The lens ROM 28 stores unique information PI of the photographing lens 104. The unique information PI has a lens identification ID and a parameter. The lens identification ID is used as an identifier for acquiring correction information (described later) specific to the photographing lens 104 for correcting the parameter from the Web server 112.
Only the photographing lens that can obtain the correction information from the Web server 112 has the lens identification ID. On the other hand, a photographic lens that cannot obtain correction information from the Web server 112 (such as a third-party photographic lens that does not have correction information in the Web server 112 or an old photographic lens that does not have a lens ROM) has a lens identification ID. Not.

The parameters are, for example, exit pupil position A, aperture efficiency B, and open F number C. The unique information PI is output to the CPU 18 via a communication line (not shown). The CPU 18 is connected to the lens ROM 28 via a communication line.
The CPU 18 detects whether or not a lens identification ID is stored in the lens ROM. By this detection, the CPU 18 can detect whether or not the photographic lens 104 is a photographic lens that can acquire correction information from the Web server 112.

When the CPU 18 detects that the lens identification ID is stored (the photographing lens is capable of acquiring correction information from the Web server 112), the correction information a corresponding to each of the parameters A, B, and C from the Web server 112 is detected. , B and c. The CPU 18 corrects the parameters A, B, and C using the acquired correction information a, b, and c.
On the other hand, when the CPU 18 detects that the lens identification ID is not stored (the photographic lens cannot obtain correction information from the Web server 112), the CPU 18 averages the correction information of all the photographic lenses using the parameters A, B, and C. Correct using the value obtained.

  FIG. 3 shows details of a main part of the ROM 16 shown in FIG. In this example, the ROM 16 has five storage areas to which address numbers A-No. Each storage area has first and second storage areas in order to store correction information in association with the lens identification ID of the photographic lens. The first storage area stores the lens identification IDn. The second storage area stores correction information an, bn, and cn (n = 1 to 5).

For example, the storage area stores the lens identification IDn and the correction information an, bn, and cn in the ROM 16 sequentially from the youngest address number (FIG. 3A). In this example, the storage area of address number A-No. 5 is an empty area since the lens identification ID and the correction information are not yet stored.
Thereafter, the CPU 18 acquires the lens identification ID 5 and parameters (FIG. 2) stored in the lens ROM. In order to correct this parameter, the CPU 18 acquires correction information a5, b5 and c5 corresponding to the lens identification ID5 from the Web server 112. The acquired correction information a5, b5 and c5 are stored in the storage area of address number A-No. 5 in association with the lens identification ID 5 (FIG. 3B). In this state, the lens identification ID and the correction information are stored in all five storage areas of the ROM 16, and there is no free area.

  Thereafter, as in FIG. 3B, the CPU 18 acquires the lens identification ID 6 and the correction information a6, b6, and c6. The acquired lens identification ID 6 and correction information a6, b6 and c6 are stored in the storage area of the address number A-No. 1 in place of the lens identification ID1 and correction information a1, b1 and c1 (FIG. 3 (c). )). That is, the lens identification ID 6 and the correction information a6, b6, and c6 are replaced with the lens identification ID1 and the correction information a1, b1, and c1 stored in the ROM 16 the oldest.

  In this example, the correction information a6, b6, and c6 is acquired in order to correct the parameter of the photographing lens that is most recently exchanged by the user. In general, the frequency with which an old lens attached to the camera body 102 before lens replacement is used by the user is less than the frequency with which the most recently replaced photographic lens is used by the user. In other words, the correction information a1, b1, and c1 corresponding to the old lens is less frequently used for parameter correction.

By replacing the correction information a6, b6 and c6 with the correction information a1, b1 and c1 which are less frequently used, even when the ROM 16 has only five storage areas as shown in FIG. Can be stored in the storage area. For this reason, the limited storage area of the ROM 16 can be used effectively.
FIG. 4 shows an exposure value correction operation in the first embodiment of the camera. The operation shown in FIG. 4 is realized by the CPU 18 (information acquisition means, correction information acquisition means, information correction means, photometric correction means, and information writing means) executing a program stored in the ROM 16.

  First, in step S100, the CPU 18 determines whether or not the lens identification ID is stored in the lens ROM 28 in order to determine whether or not the photographic lens 104 is a photographic lens that can acquire correction information from the Web server 112. Is detected. If the lens identification ID is stored (the photographing lens is capable of acquiring correction information from the Web server 112), the process proceeds to step S102. If the lens identification ID is not stored (correction information cannot be acquired), the process proceeds to step S118.

In step S <b> 102, the CPU 18 detects whether correction information a, b, and c corresponding to the lens identification ID is stored in the ROM 16. If correction information a, b, and c are stored, the process proceeds to step S116. If the correction information a, b, and c are not stored, the process proceeds to step S104.
In step S <b> 104, the CPU 18 detects whether or not the Web server 112 is connected to the I / F circuit 18 via the personal computer 106 and the Internet 110. When connected to the Web server 112, the process proceeds to step S106. If not connected to the Web server 112, the process proceeds to step S118.

In step S <b> 106, the CPU 18 detects whether correction information a, b, and c corresponding to the lens identification ID can be transmitted from the Web server 112. If it is detected that transmission is possible, the process proceeds to step S108. If it is detected that transmission is impossible, the process proceeds to step S118.
In step S108, the CPU 18 stores the lens identification ID and the correction information in any of the five storage areas (first and second storage areas) (FIG. 3) to which the address numbers A-No. It is detected whether there is a free area for storing a, b, and c. If it is detected that there is a free area, the process proceeds to step S110. If it is detected that there is no free area, the process proceeds to step S112.

In step S110, the CPU 18 receives the correction information a, b, and c from the web server 112, and stores the received correction information a, b, and c in the empty area in association with the lens identification ID. Thereafter, the process proceeds to step S116.
On the other hand, in step S112, the CPU 18 drives the liquid crystal monitor LCD 20, and replaces the correction information a1, b1 and c1 transmitted from the web server 112 with the oldest stored correction information a1, b1 and c1 (FIG. 3). Then, a screen for the user to select whether to store in the ROM 16 by operating the selection switch SW3 (described in FIG. 1) is displayed. Thereafter, the process proceeds to step S114.

  In step S114, the CPU 18 operates the switch SW3 to select that “the correction information a, b, and c is replaced with the oldest stored correction information a1, b1, and c1 and stored in the ROM 16” is selected. If detected, the process proceeds to step S110. At this time, the user may select a storage area (correction information) to be replaced. When the CPU 18 detects that the user operates the switch SW3 and selects “do not replace”, the process proceeds to step S118.

In step S116, the CPU 18 corrects the exposure value of the camera 100 using the correction information a, b, and c stored in the ROM 16 and the parameters A, B, and C in the unique information PI. Is calculated. In this example, the CPU 18 calculates the correction value Z using the following Z value arithmetic expression (1).
Z = a1 * A + b1 * B + c1 * C (1)
When the correction value Z is calculated, the process proceeds to step S120. In step S <b> 120, the CPU 18 corrects the exposure value of the camera 100 using the correction value Z. Then, the exposure value correction operation in the first embodiment of the camera ends.

  On the other hand, if the Web server 112 is not connected to the I / F circuit 18 in step S104, or if it is detected in step S106 that the correction information a, b, and c cannot be transmitted from the Web server 112, or If it is detected in S114 that “no replacement” is selected, in step S118, in this example, the CPU 18 calculates a correction value using a value obtained by averaging correction information of all the photographing lenses. Thereafter, the process proceeds to step S120.

As described above, in the present embodiment, the correction information a, b, and c is acquired based on the lens identification ID of the photographing lens 104. By correcting the exposure value using the correction information a, b and c and the correction value Z calculated by the parameters A, B and C, the subject can be imaged with the exposure value optimally corrected. For this reason, the brightness of the subject image can be optimized.
The camera body 102 is connected to the Internet 110 via a personal computer 106. For this reason, it is not necessary to install the hardware necessary for connection to the Internet 110 in the camera body 102. Therefore, the mechanism of the camera body 102 can be simplified. Since the number of manufacturing steps and the number of parts for manufacturing the camera body 102 can be reduced, the manufacturing cost of the camera body 102 can be reduced.

FIG. 5 shows a second embodiment of the camera of the present invention. FIG. 5A shows a camera 200 (for example, a digital camera) to which the present invention is applied. Hereinafter, differences from the camera 100 of the first embodiment will be mainly described.
FIG. 5A shows a camera 200 (for example, a digital camera) to which the present invention is applied. As in FIG. 1, the photographic lens 104 is attached to a lens mount formed on the camera body 202, and the camera body 202 and the photographic lens 104 are connected via a communication line.

The camera body 202 of the camera 200 communicates wirelessly via a wireless link (transmission path) in order to acquire correction information of the taking lens 104 from the Web server 112. The wireless link is formed in accordance with, for example, IEEE (Institute of Electrical and Electronics Engineers) 802.11b of a wireless local area network (LAN).
FIG. 5B shows an access point (line terminal device) 114. The access point 114 communicates with the camera body 202 in a wireless manner via a wireless LAN. The access point 114 connects each terminal including the camera 200 connected to the wireless LAN to the Internet 110 (computer network). Each terminal is connected to the Web server 112 via the Internet 110.

The camera 200 acquires correction information of the photographing lens 104 from the Web server 112 via the access point 114 and the Internet 110. The acquired correction information is stored in the ROM 16 (FIG. 6) via an antenna (described later) and a wireless I / F circuit (described later) incorporated in the camera 200.
FIG. 6 shows an internal configuration of the camera 200 and the photographing lens 104 shown in FIG. The same elements as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In this embodiment, the camera 200 includes an antenna 30 and a wireless I / F circuit 32 (wireless connection means) instead of the I / F circuit 20 of the first embodiment. A program stored in the ROM 16 to be executed by the CPU 18 is different from that of the first embodiment of the digital camera. Other configurations are the same as those of the first embodiment.

The antenna 30 includes correction information a and b corresponding to the parameters A, B and C of the photographing lens 104 transmitted from the Web server 112 (FIG. 5) via the access point 114 (FIG. 5) and the Internet 110 (FIG. 5). And c.
The wireless I / F circuit 32 acquires correction information a, b, and c received by the antenna 30. The CPU 18 calculates the correction value using the correction information a, b, and c acquired by the wireless I / F circuit 32 and the parameters A, B, and C.

  FIG. 7 shows an exposure value correction operation in the second embodiment of the camera. The operation shown in FIG. 7 is realized by the CPU 18 (information acquisition means, correction information acquisition means, information correction means, photometric correction means, and information writing means) executing a program stored in the ROM 16. FIG. 7 is the same as FIG. 4 except that step S104 of the first embodiment (FIG. 4) is replaced with step S200.

After steps S100 and S102 are executed, the process proceeds to step S200. In step S <b> 200, the CPU 18 detects whether or not the Web server 112 is connected to the wireless I / F circuit 32 via the access point 114 and the Internet 110.
When connected to the Web server 112, after steps S106 to S120 are executed, the exposure value correction operation in the second embodiment of the digital camera ends. If not connected to the Web server 112, the steps S118 and S120 are executed, and then the exposure value correction operation in the second embodiment of the digital camera ends.

  As described above, in this embodiment, the same effect as that of the first embodiment can be obtained. Furthermore, the camera body 202 is connected to the Internet 110 via the access point 114 by a wireless LAN. In order to connect the camera body 202 to the Internet 110, it is not necessary to attach a wired cable to the camera body 202. Since there is no restriction due to the cable length, the camera body 202 can be easily moved while connected to the Internet 110.

In the first embodiment described above, the example in which the camera 100 is connected to the personal computer 106 via the USB cable 108 has been described. The present invention is not limited to such an embodiment. The camera 100 may be connected to the personal computer 106 using an IEEE 1394 cable.
In the first and second embodiments described above, examples in which digital cameras are used as the cameras 100 and 200 have been described. The present invention is not limited to such an embodiment. As the cameras 100 and 200, a silver salt film type camera may be used.

  In the first and second embodiments described above, the CPU 18 described the example of receiving the correction information a, b, and c corresponding to the lens identification ID from the Web server 112. The present invention is not limited to such an embodiment. The CPU 18 may receive correction information a, b, and c corresponding to the lens identification ID and the camera identification ID that is data for identifying the cameras 100 and 200 from the Web server 112.

In the first and second embodiments described above, the CPU 18 has described the example of calculating the correction value for correcting the exposure value. The present invention is not limited to such an embodiment. The CPU 18 may calculate an aberration correction value in order to correct the aberration of the lens system 26.
As mentioned above, although this invention was demonstrated in detail, said embodiment and its modification are only examples of this invention, and this invention is not limited to this. Obviously, modifications can be made without departing from the scope of the present invention.

  The present invention is applied to a camera that corrects optical characteristic information of a photographing lens using correction information.

It is a block diagram which shows 1st Embodiment of the camera of this invention. FIG. 2 is a block diagram illustrating an internal configuration of a camera 100 and a photographing lens 104 illustrated in FIG. 1. FIG. 3 is a block diagram showing details of a main part of a ROM 16 shown in FIG. 2. It is a flowchart which shows the correction | amendment operation of the exposure value of 1st Embodiment of the camera of this invention. It is a block diagram which shows 2nd Embodiment of the camera of this invention. It is a block diagram which shows the internal structure of the camera 200 and the photographic lens 104 which were shown in FIG. It is a flowchart which shows the correction | amendment operation | movement of the exposure value of 2nd Embodiment of the camera of this invention.

Explanation of symbols

10 Photometric sensor 12 CCD
14 A / D conversion circuit 16 ROM
18 CPU
20 I / F circuit 22 LCD monitor LCD
24 Bus 26 Lens system 28 Lens ROM
30 Antenna 32 Wireless I / F circuit 100, 200 Camera 102, 202 Camera body 104 Photo lens 106 Personal computer 108 USB cable 110 Internet 112 Web server 114 Access point

Claims (5)

Information acquisition means for acquiring lens identification information and optical characteristic information as specific information of the shooting lens from the shooting lens mounted on the camera body;
Connection means for connecting the camera body to a computer network;
When the lens identification information is acquired from the photographic lens by the information acquisition means, correction information corresponding to the lens identification information and for correcting the optical characteristic information acquired from the photographic lens, An operation of acquiring the correction information from the computer network when the lens identification information is not acquired from the photographing lens by the information acquisition unit while being acquired from the computer network based on the lens identification information. Correction information acquisition means using as a correction information a value obtained by averaging correction information of all the stored photographic lenses without performing ,
An information correction unit that corrects the optical characteristic information using the correction information acquired by the correction information acquisition unit. The camera of claim 1,
The connection means comprises a communication terminal connection means for connecting the camera body to the communication terminal in order to connect the camera body to the computer network via a communication terminal. The camera of claim 1,
The camera according to claim 1, wherein the connection means includes wireless connection means for connecting the camera body to the computer network in a wireless manner. The camera of claim 1,
Metering means for metering light incident from a subject via the photographing lens mounted on the camera body;
A camera comprising: a photometric correction unit that corrects a photometric result obtained from the photometric unit using the optical characteristic information corrected by the information correcting unit. The camera of claim 1,
Storage means having a plurality of storage areas for storing the correction information in association with the lens identification information;
Information writing means for writing correction information in the storage means,
The information writing means sequentially writes the correction information acquired by the correction information acquisition means in association with the lens identification information into the empty area when the storage area is empty, and when the storage area is empty. The correction information acquired by the correction information acquisition means is replaced with the oldest written correction information and stored,
The information correction means corrects the optical characteristic information using the correction information stored in the storage means and corresponding to the photographic lens mounted on the camera body.

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